The present invention relates to a pavement material, in particular to an asphalt pavement material used to construct or repair a road.
In prior art, an asphalt pavement material for the construction or the repairing of a road was usually a mixture containing an asphalt and several kinds of aggregates (including crushed stone, coarse sand and fine sand). If a color pavement is required, a kind of pigment having a desired color should also be added into the mixture. Further, if it is necessary to achieve a desired water penetrability throughout the pavement material, what people have to do is to select an appropriate size for the crushed stone, without having necessity to change the composition of the mixture (pavement material) itself.
However, since the above-mentioned aggregates (crushed stone, coarse sand and fine sand) are all taken from natural fields such as mountain, river, seaside), and since there is an increasingly growing needs for road construction, people begin to worry that these naturally obtainable materials will soon be used up in near future.
In order to solve the above problem, there has been suggested in Japanese Patent Application Laid-open No. 7-299440 that waste materials from construction fields be processed into aggregates which may be mixed with an asphalt to prepare an asphalt pavement material.
But, if the suggestion offered in Japanese Patent Application Laid-open No. 7-299440 is adopted, it is necessary to transport these construction waste materials from construction fields to a specific plant where a set of comparatively complex equipments and a relatively difficult technique are needed to carry out necessary treatment on the waste materials so as to produce an aggregate which has the same shape and property as a natural aggregate.